hi msd129
i just want to suggest these points just in case until now you haven't made up your mind yet. if you don't plan on SLIng or Xfiring, then get the Asus p8z77-v M motherboard (its the smaller version of the z77 which only has 1 PCIe 3.0). aside from that, it can support your every hardware all the same when you buy the ATX version. and of course, its cheaper.
also, so that you can make use of the Intel Smart Response technology of your motherboard (comes in z77 mobos) which makes your SSD a cache, then i suggest you get a low capacity SSD just to utilize this technology. there is a huge improvement in boot, load, read, etc speeds. just get at most 60GB. i suggest the OCZ agility 3, which tom's hardware recommends in the 60GB area. and if you don't download or store much, cut your main storage to 750GB or maybe 500GB from 1TB.
i also think 7850 is a really nice card because its overclocking potential is quite high which essentially increases its value. even if you don't want to overclock, 7850 will still serve you for a long time. i just think 670 is overkill and its too expensive. but its up to your budget. anyway, if you want the 7850, get the Asus DirectCuII. Sapphire is also good, but i've read in many threads that Asus is more reliable. and it looks a lot better xD
you must also increase the wattage of your PSU. make it at least 600W, get the seasonic or corsair. its up to you to decide wether to get a modular or non modular model. i think 500W is just enough but you would want that extra power allowance.
anyways, good luck! all these information i've learned through intensive research. hope these helped!